Steam-turbine.



No. 726,315. PATENTED APR. 28, 1903. T. G. E. LINDMARK.

STEAM TURBINE.

APPLIOATION FILED DEC. 4, 1902. I

K0 MODEL. 2 SHEETS-SHEET 1.

WITNESSES INVENTOR PATENTED APR. 2s, 1903.

T. G. E. LINDMARK. STEAM TURBINE. APPLICATION I'ILED'DEO. 4, 1 902.

2' SHEETS-SHEET 2.

N0 MODEL.

INVENTOR m. Z. amaal/2' BY ATTORNEY ms annals w-rcws c'o. www.mnaWASHING'ION. u c

ilnirnn Sta i ns ATET Fries.

STEAM-TURBINE.

SPECIFICATION formingpart of Letters Patent N 0. 726,315, dated April28, 1903.

Application filed December 4,1902. Serial No. 138,821. (No model.)

To (tZZ whom, it petty concern:

Be itknown that 1, Tons GUsTAF EMANUEL LINDMARK, a subject of the Kingof Sweden and Norway, residing at Stockholm, Sweden, have invented a newand useful Improvement in Steam-Turbines, of which the following is aspecification.

The object of the invention is to increase the efficiency of thesteam-turbine wheel.

The invention consists in the combination, with a steam-turbine of thetype wherein the steam from the interior of the wheel is emitted in acompact jet, of a chamber constructed and arranged to receive said jet,the said chamber increasing in cross-sectional area in a direction atright angles to the direction of said jet; also, in combination withsaid turbine, an annular chamber, as set forth; also, in combinationwith said turbine emitting a multiplicity of jets, a multiplicity ofcham bers receiving said jets and constructed as set forth.

In the accompanying drawings, Figure l is a section of wheel and casing011 the lineccx of Fig. 2. Fig. 2 is a section on the line y y ofFig. 1. Fig. 3 is a diagram illustrating the shape of the solidsteam-jet emitted by a wheel of the type hereinafter referred to. Fig.'

4 is a diagram illustrating the division of the annular passagereceiving the jets from the wheel into a multiplicity of passagescorresponding in number to the number of escapeoutlets between thewheel-buckets.

Similar numbers of reference indicate like parts.

1 is the wheel-casing, and 2 the wheel, which is supported on the hub 3,fast on shaft 4.. The wheel-body is hollow. The wheel-head 5 is flangedat 6, so that an annular inlet 7is formed around the hub. In thecircumferential periphery of the wheel is the annular steam-outlet 8,which is divided into a number of smaller outlets 10 by thewheel-buckets 11. The outlet 8 corresponds to and registers with anannularinlet 12, formed in the casing and communicating with the passageor chamber 13, which passage, as shown in Fig. 1, has diverging walls.Passage 13 communicates with the surrounding chamber 14, which opensinto the exhaust 15. Steam entering the inlet 16 in the casing passes tothe chamber 17 and thence by the inlet 7 to the infirst, so-calledimpact-wheels, in which thestearn in the form of a jet from a nozzledisposed exterior to the wheel strikes a bucket, usually of U shape anddisposed at and transversely to the circumferential periphery of thewheel; second, reaction-wheels, in which the steam entering thewheel-body escapes at the periphery through the intervals betweeninclined buckets there disposed.

In the first-named class of wheels the steamjet meets the inner side ofone leg of the U- shaped bucket, sweeps around the interior of thebucket, and finally escapes in a direction nearly the opposite to thatat which it entered. Inthesecond class the steam escapes in the form ofdirectly-emitted jet. By long experimenting with both classes of wheelsI have discovered that the jet passing from thebucket of an impact-wheelis in the form of a very thin skin or sheet, so that the entireexhaustis made up of a number of these thin sheets with empty intervals orspaces between them. On the other hand, the jet from a reaction-wheel iscompact and fills the interstitial spaces between the buckets, so thatall around the wheel there is not a succession of thin sheets, but auniform compact outflow of steam. The compact jet of steam escapingbetween successive buckets is illustrated by the dotted lines, Fig. 3.It is well known in the art that by means of a chamber receiving thewaste steam escaping from the buckets of a steam turbine and increasingin cross sectional area the expansion of the steam admitted to the wheelcan be extended to a certain degree, whereby the greatest possibleeffect from the steam which passes through the turbine is obtained. Alsoif the turbine is running non-condensing a certain vacuum may bemaintained around the wheel, whereby the resistance offered to therotation of the wheel by the medium in which it works is diminished.This'is fully disclosed in British Patent No. 20,603, November 26, 1891,to Carl G. P. De Laval; but in said De Laval device the type of wheelemployed is of the impact class, from which,

as I have explained, the steam is emitted in thin sheets. Nowexperiments have shown that the efficiency of said exhaust-chamber isgreatly reduced if the steam enters the chamber in many thin sheetscompared with the efficiency obtained when the steam enters in a compactjet. To meet the difficulty which would follow the entrance of thesesheets directly into the diverging chamber, De Laval makes the sides ofsaid chamber convergent for a short, distance from the place of entranceof the steam. The effect of this. is to collect the sheets, and so bringthem into a more compact jet before their entrance into the divergingpart of the chamber. It is apparent, therefore, that the De Laval devicediscloses an impact-turbine provided with a diverging exhaust-nozzle'andthat the thinsheet difilculty incident tothis typeof turbine is met bythe expedient of the initial convergence in the exhaust-chamber.

In United States Patent to Terry,No.636,867,

. November 14, 1899, exactly the same device is represented as in the DeLaval British patcut, with the omission of the De Laval initialconvergence in the exhaust-chamber, and

therefore with no means at all for meeting the l disadvantages of thethin sheets.

Now myinvention consists in this,thatwith anozzle or chamber on theexhaust sidewhich increases in cross-sectional area in the'direcv tionat right angles to that of the compact jet of steam admitted into it Icombinea turbine of the reaction type constructed to pro duce suchcompact jets, and thus I get the conditions of maximum efficiency. Thesaid i nozzle may be in the form of a continuous ring surrounding theescape-on tlet 8, or it may be divided into enlarging chambers by meansof partitions 16, as shown in Fig. Land in dotted lines, Fig. 2.

I claim 1. In combination with a steam-turbine of the type wherein steamfrom the interior of the wheel is emitted in a compact jet, an

elongated chamber directly receiving said jet;

the said chamber-increasing in cross-sectional area from inlet to outletand being disposed tangentially the wheel circumference in the line ofsaid jet, substantially as described.

2. In combination with a steam-turbine of the type wherein steam fromthe interior of the wheel is emitted at the periphery thereof in acompact annular jet, an annular chamber receiving said jet directly fromsaid wheel and increasing in cross-sectional area in a direction atright angles to the direction of said jet-in passing from said chamber,substantially as described.

3. In combination with a steam-turbine of the type wherein steam fromthe interior of the wheel is emitted at the periphery thereof in aplurality of compact jets, a casing having an annular passagesurrounding said wheel and directly receiving said jets; and in saidpassage partitions dividing the same into I chambers'disposedtangentially the wheel circumference and in the line of direction of thereceived jets and increasing in cross-sectional area from inlet tooutlet, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of

